Well torpedo firing heads



May 12, 1959 Gf E. ToLAND WELL ToRPEDol FIRING HEADS 5 sheets-smet 1 Filed sept. 26. 1952 May 12` 1959 G. E. TOLAND 2,885,959

WELL TORPEDO FIRING HEADS Filed sept. 26, 1952 s sheets-sheen 2' May 12, 1959 G. E. TOLAND WELL TORPEDO FIRING HEADS 5 Sheets-Sheet 3 Filed Sept. 26, 1952 FIG. I3

FIG. I4

I'NVENTOR. Gayle E. Toland FIG. Il

lufmmfy )-VJ( United States This invention relates to improvements in well torpedoes and tiring heads therefor.

The primary object of this invention is the provision of an improved firing head construction for well torpedoes, particularly well adapted for the shooting of extremely deep wells with safety and efficiency.

I have found that the usual firing heads for well torpedoes will not operate eiectively in wells at levels below 5,000 feet. Due to certain pressures within the well acting upon the torpedo, it has been found that in wells at levels below 5,000 feet the firing pin will gradually impress itself into the cartridge primer cap, with theresult that when the torpedo is at the desired level the primer cap has been penetrated to such an extent that the torpedo will fail to explode upon dropping the trigger Weight, conventionally known as go-devil. I have therefore provided improved means to prevent such premature destruction of the cartridge.

A further object of this invention is the provision of an improved trigger weight for ring well torpedoes.

A further object of this invention is the provision of improved means for reinforcing an oil Well torpedo, so that the trigger weight will not result in injury to the torpedo bucket when dropped within deep wells.

Other objects and advantages of this invention will be apparent during the course of the following detailed description.

In the accompanying drawings, forming a part of this specication, and wherein similar reference characters designate corresponding parts throughout the several views:

Fig. 1 is a vertical cross sectional View taken through a Well casing, showing in vertical cross section the irnproved torpedo structure associated therewith.

Fig. 2 is a side elevation of the upper section of they tiring head.

Fig. 3 is a side elevation of the lower section of the firing head.

Fig. 4 is an enlarged fragmentary cross sectional View taken through the telescopically disposed upper and lower sections of the firing head, showing the priming charges and tiring pin structure disposed therein, including the means to safety the same until the torpedo has reached a desired level in the well.

Fig. 5 is a cross sectional View of a modified form of means to safety the tiring head.

Fig. 6 is a top plan view of the upper section of the ring head; the View being taken substantially from the position of the line 6-6 of Fig. l.

Figs. 7 and 8 are cross sectional views taken substantially on the respective lines 7-7 and 8--8 shown in Fig. 4 of the drawings.

Fig. 9 is a transverse cross sectional view taken substantially on the line 9-9 of Fig. 5.

Fig. 10 is a fragmentary cross sectional View showing the torpedo in side elevation, within a vertical sectional View of the casing; ythe view more particularly showing an improved trigger weight for firing the torpedo, commonly known as a go-devil.

Fig. 11 is a side elevation of the trigger Weight.

Fig. 12 is a side elevation of a bottom reinforcing device for the bucket, to prevent a rupture incidental to use of the torpedo in deep Wells.

Fig. 13 is a plan view of the trigger weight shown in Fig. 1l, the same being taken substantially from the position 13-13 shown in Fig. 11.

Fig. 14 is a transverse cross sectional view taken substantially on the line 14-14 shown in Fig. 11.

In the drawings, the letter A may generally designate a torpedo adapted for association within the well casing or drill part structure B. The torpedo A preferably consists of a main container or bucket C adapted to receive an explosive charge, and having associated therein the firing head structure D. The latter receives priming cartridges E and F with a firing pin G therebetween.

The drill pipe or Well casing structure B includes the usual pipe sections 10, 11 etc.; adjacent ends being connected by collars 12. Normally they leave a shoulder 13 facing downwardly at the inside of the passageway 14 of the pipe.

The bucket C preferably is of aluminium or some other light weight metal or material, including a cylindrical wall structure 20 having a tapered bottom wall 21. The bucket cylinder 20 at its upper ends supports a bail 24 to which a flexible supporting cable 25 may be attached, for lowering of the torpedo into the well.

Anchoring prongs 26, of flexible spring material, are se-` cured upon the bucket 20, by means of soldering or welding; the upper ends being free to be sprung laterally.

When the torpedo structure is lowered into the Well casing passageway 14 the upper ends will lightly engage the inner wall structure of the casing and anchor against the shoulder 13 when the bucket is pulled back into position at the location where the explosion is to take place.

It is conventional practice to locate the main explosive charge directly in the bucket, and to dispose therein a priming charge secured within a suitable ring mechamsm.

The improved iiring head structure D of the present invention consists of upper and lower sections 35 and 36 respectively. They are preferably formed of zinc.

Experiments conducted by me have proven that conventional ring heads will fail, in a certain percentage of p instances, to explode when used in wells over 5,000 feet in depth. This is due to certain pressures gradually imposed upon the firing mechanism as it is lowered, causing the gradual penetration (without detonation) of the ring pin points into the primer caps of the cartridges,

, so that when the trigger weight is lowered the ring head will fail to explode. I have therefore so arranged connection of the firing head sections 35 and 36 that the lowering of the firing head into deep wells Will not cause pre-.

mature penetration of the cap ends of the cartridges.

The upper section 35 comprises a main body 37 of a length such that the upper end thereof projects from the top opening 30 of the bucket C. The body portion 37 is preferably formed of integral vanes, as shown in dotted lines in Fig. 6. At their upper ends the vanes are enlarged with a taper to support a preferably integral at head or disc 40. The latter is provided with an opening 41 therein through which the supporting cable 25 is threaded. The lower end of the body portion 37 has a small cylindrical shank 42 integral therewith and externally screw threaded at 43 for receiving thereon a movement preventing nut 44. Upwardly from the extreme lower end the section 35, is provided with a carassenso The lower tiring head `section 36 comprises a cylindrical shaped tubular portion 50 having axially therein a cartridge receiving chamber 51 for the cartridge F and an upper compartment 52 for telescopicall-y and slidably receiving the lower screw threaded end of the shank 42 of the upper tiring -head section 3S. At the juncture of the compartments 51 and S2 there is an annular shoulder or seat 53 adapted to receive thereon the rim end 54 of the cartridge F, to support the said cartridge `in inverted position in the compartment 51.

The lower end of the section 36 is provided with integrally connected vanes 55 andthe extreme lower tip of the section 36 is in the shape of an inverted cone, adapted to center and seat in the bucket C vof the torpedo in a 'manner to be subsequently described.

Referring to the mode of assemblage, the `primer cartridge F is disposed in `the compartment 51 of the lower `section 36 of the tiring head. The cartridge E is disposed in the upper section 35. The firing pin structure G, is preferably of steel and includes a cylindrical body portion adapted to slidably tit in the chamber 52. It is tapered at its upper and lower ends and terminates in tiring pins 60 and 61. The tiring pin structure is lowered along the passageway 52 and brought .to rest against the primer end of the Vcartridge '.F. The screw threaded end of the shank 42 With the `cartridge E in place is then slipped into the compartment or socket .52

until the primer end of the cartridge E rests against the l tiring pin 60.

In order to render the tiring head eiective for positive firing in deep Wells after the assemblage of the cartridges n and tiring pin structure in the sections 35 and 3.6, the nut 44L is backed along the screw threaded portion 43 `sutiiciently to permit pin contact of the ring pin structure with the primer ends of the cartridges. The nut 44 is then threaded downwardly until it engages the top edge 70 of the section 36. A slight turn of the same will then slightly space the pins 60 and 61 from the primer ends of the cartridges, and the sections 35 and 36 then cannot be telescopically moved towards each other to cause premature indentation of the priming ends of the cartridges.

It is essential that the priming cartridge receiving chambers of the tiring head be sealed against admission of moisture. This is accomplished by winding waterproof rubber tape 80 at the exposed juncture ofthe tiring head sections 35 land 36, as shown in Fig. 4 of the drawings. The nut 44 is covered by the winding of the tape and positively held in its threaded position upon the section 35 against rotation. The rubber tape is then encased by winding of friction tape 81 thereover to prevent damage to the rubber tape 80, as by oil. The entire joint thus in eiect provides a compressible rubber sleeve which seals off the cartridge chambers against admission of moisture.

The chamber of the bucket C has a quantity of mud and sand, shown at 90. On top of it is a layer of nitroglycerine, preferably in the form of nitrogelatin, designated at 91. There is another layer of mud and sand or other materials 92, on top of the explosive nitrogelatin. The length relation of the tiring head when assembled, as above described, is such that the tiring pin and primer cartridges will lie within the area of the explosivematerial 91.

The cable 25 is ordinarily of flexible steel wire, about .066 inch in diameter. The torpedo Vhead is lowered by it, the cable being run through a metering device to gauge the desired level. When the level, at which the well is to be shot, is reached, the bucket is maneuvered to anchor the prongs 26 against the shoulder 1-3 Within the casing.

Ordinarily the weight or go-devil to set `off the eX- plosion is a section of pipe threaded upon the `cable 25. I have found that it is not yvery effective, because sometimes in shooting ldeep wells the edge of the pipe Will strike too far to the side lof the head or disc 40 and the cartridges will not explode. In order that the trigger weight will properly hit the head or discs 40, I have provided a new type yof go-devil comprising a solid length of rod, designated at in Fig. l1 of the drawings. To its upper end is laterally secured an eyelet 101, preferably welded, as shownat 102 to the top of the rod 100 (see Fig. 13). r1`he rod 100 at its lower end is provided with a laterally disposed cable receiving sleeve 103, of a desired length, Welded at 104, to the rod 100. The length and diameter of the sleeve 103 are such that the sleeve 103 will not have too free lateral play upon the cable 25. The rod 100 is preferably conventional 7/8 inch sucker rod, approximately ten or eleven feet in length. With the lateral play of the rod 100 thus limited, so vfar as the cable 25 is concerned, and due to the length of `this rod, the godevil will have a positive hitting action upon the upper section of the firing head, so as to effectively re the priming charges.

I have also found that in the use of torpedoes within deep wells, using the equipment above described, it has occasionally happened that the impact of the go-devil upon the tiring head will force it through the bottom of the bucket. To prevent this I have provided a conical shaped Weight adapted to tit within the tapered bottom 21 of the bucket C. This weight is constructed to assist in centering the tiring head and also to distribute shock incident to impact of the go-devil over a large area ofthe bottom of the bucket C.

The weight 110 has a central co-axial opening 111 to receive the tapered end `56 of the firing head section 35, for properly `centering the tiring head. The weight also plays an important -part in the distribution vof the shock so as `to prevent rupture of the bucket and assists in easy lowering of the torpedo.

In tiring of the torpedo, the go-devil or weight is applied kupon the cable as designated, and dropped along the cable 25. When it hits the disc 40 of the tiring head the force will shear the nut 44 from `its supporting threads and cause the firing of the cartridges in a manner which is apparent.

In lieu of the nut 44 I may use a shear pin structure, such as shown at in Fig. 5. The upper section 36a of the firing head may be provided with diametrically aligned openings 121 -to receive the pin 120. A series of these openings 121 may be provided if desired, and after assembly of the sections of the tiring head, to the point where the firing pins rest against the primer ends of the cartridges, the shear pin 120 will be placed in the desired openings 121 so as to prevent premature indentation of the ring pin points in the cartridges during lowering of the torpedo. This shear pin structure, and the joint of the sections shown in Fig. 5 are covered with sealing tape. The same reference characters are applied to corresponding parts of the invention as in Figs. 4 and 5.

Various changes in the shape, size, and arrangement of parts may be made to the form of invention herein shown and described, without departing from the spirit of the invention or scope of the claims.

I claim:

1. A firing head for well torpedoes comprising a pair of elongated sections, one of said sections having a chamber therein adapted to slidably receive the adjacent end of the other section, said sections at their proximate ends having cartridge receiving chambers therein, firing pin means for the cartridges located between said chambers, and shear means on one of said sections normally capable of movement away from the other section and in position to engage the end of the other section to limit the proximate movement of said sections longitudinally.

2. In a firing head for well torpedoes the combination of a pair of elongated sections each having a cartridge receiving chamber therein, one of said sections also having a chamber to telescopically slidably receive the `cartridge end of the other section, the last mentioned section ybeing externally screw threaded and having an adjustable shear nut thereon engaging the adjacent end margin of the other section to limit the proximate telescopic dis- 5 position of said sections for the purpose of preventing premature explosion of cartridges when in said cartridge chambers.

3. In a firing head structure for 'torpedoes the combination of a pair of elongated sections one of which has an end which telescopes within the other section, the latter section being provided with a chamber to receive the telescoping end of the other section, said sections being provided With chamber providing means for receiving an explosive charge and a firing mechanism, the section which telescopes within the chamber of the other section being externally screw threaded and the threads being of such diameter that the threaded end may be telescoped by endwise sliding and without turning into said chamber of the other section and a shearing nut threaded upon said screw Ithreads, the screw threads being of suiiicient length along the `section whereby to externally extend beyond the adjacent end of the other section so that the nut engages the adjacent end of the adjacent section to limit proximate movement of said sections in a telescopic relation for the purpose of preventing premature explosion of said charge.

4. A tiring head as described in claim 3 in which each of said sections is provided with a cartridge receiving chamber of the same diameter, the first mentioned chamber of the section which telescopically receives therein the screw rthreaded end of the other section being larger in diameter than the cartridge chambers and a tiring pin in the larger chamber portion lying between said cartridge chambers.

References Cited in the le of this patent UNITED STATES PATENTS 

